Q0068
Long-duration storage becomes more useful when the system regularly needs energy for longer than conventional lithium-ion BESS is economically designed to provide, especially across overnight, multiday or infrequent but severe deficits. The crossover depends on how often the asset cycles, the value of dependable capacity, charging-energy availability, efficiency and the relative cost of adding hours. Short-duration BESS can still remain better for fast response and daily peaks.
Calling every storage need a battery problem can create an expensive stack of short-duration systems that empties before a long event ends. Matching duration to the actual net-load gap helps Malaysia avoid overbuilding storage while preserving reliability as solar penetration rises.
Frequency response may require seconds or minutes. Solar ramping and evening peaks often require several hours. Overnight, multiday weather events and seasonal imbalance require progressively more stored energy. US DOE uses ten hours or more as a programme definition for long-duration energy storage, but the economic crossover is not a universal threshold.
A storage project has a power rating in MW and an energy rating in MWh. Some technologies add duration mainly by expanding a reservoir, electrolyte, cavern or thermal store, while batteries add more cells. Technologies with higher power-system cost but cheaper stored energy can become competitive at longer duration.
High-efficiency lithium-ion BESS may be attractive when it cycles most days. A lower-efficiency, long-life technology may suit infrequent long events if its energy capacity is cheap and it retains charge with low standing loss.
The first four-hour battery can reduce an evening peak. As more short-duration storage is added, the remaining reliability challenge may shift to a later hour or multiday period, increasing the marginal value of longer duration.
Fast batteries, demand response, hydro, transmission and long-duration storage can work together. The correct comparison is the least-cost system portfolio under the same reliability target, not the levelised cost of one technology in isolation.
Solar-heavy systems often need intraday shifting first. Multiday and seasonal storage becomes more relevant only after renewable output, demand, interconnection and flexible generation create sustained energy deficits that cannot be managed more cheaply elsewhere.
HELP BUILD THE ANSWER
Have a useful source, first-hand experience or a different interpretation? Help us strengthen this brief by sharing evidence, filling a gap or suggesting a correction.
Economists, engineers, developers, investors, researchers, regulators and energy users see different parts of the transition. Tell us what you think deserves investigation.
Submit a questionQuestions create opportunity. Understanding where the energy transition is heading helps reveal the technologies, projects, capital and expertise that will be needed next.
The solutions that turn open questions into deployable answers — from storage chemistries to grid intelligence.
The pipeline of solar farms, substations and interconnections waiting to be built and financed.
Where investment flows next as the transition reshapes risk, return and the shape of the market.
The engineers, economists and regulators whose knowledge decides how fast the answers arrive.